Unittesting in static libraries

[Steven Schveighoffer]

On Mon, 19 Sep 2011 22:40:06 -0400, Rainer Schuetze <r.sagitario at gmx.de>  
wrote:

>
>
> On 9/19/2011 3:55 AM, Steven Schveighoffer wrote:
>> On Sat, 17 Sep 2011 01:34:35 -0400, Rainer Schuetze <r.sagitario at gmx.de>
>> wrote:
>>
>>> I think the main issue here is that a module that is compiled to a
>>> library, is split into a lot of small "object files" (one for each
>>> function or global variable) before being combined to the library.
>>> This allows the linker to just take the actually referenced parts and
>>> leave out anything that is never called.
>>>
>>> The unit tests are only referenced from the module info, so it might
>>> work if you have a reference to it in your main executable.
>>> Another workaround would be to build the library in two steps,
>>> compiling to normal object files first, then binding these to a
>>> library (shameless ad: "separate compile and link" in Visual D):
>>>
>>> dmd -unittest -c -od. test1.d test2.d
>>> dmd -lib -oftest.lib test1.obj test1.obj
>>>
>>> so it avoids breaking up the modules. the -od. is needed to not just
>>> build a single object file.
>>
>> The output from these lines should be identical to:
>>
>> dmd -unittest -oftest.lib -lib test1.d test2.d
>>
>> If it's not, that's a bug.
>>
>
> It's different, and it is meant as a feature. As described above, a  
> module is split into a number of object files, reducing dependencies  
> between the modules in the library.
>
> I'm not sure it is a good feature, though, because it has some side  
> effects: the static constructors/destructors in a module are magically  
> tied together, but the unittests are not. Also, the debug info is  
> missing for classes/structs if the init member is never referenced (see  
> http://d.puremagic.com/issues/show_bug.cgi?id=4014 ). Last time I tried,  
> disabling the splitting caused other troubles as described in the bug  
> report.

Oh yes, I actually remember looking at the archive generated by -lib for  
another reason.  Adding a unit test caused a larger library to be output  
even when -unittest was not passed!  See here:  
http://d.puremagic.com/issues/show_bug.cgi?id=5560

So I can see why this happens now, but regardless of the cause, if there  
is no way to access unit tests compiled into the library, that is *not* a  
feature, it's a bug.

-Steve